No one likes to hear big lists of rules and things you're not supposed to do. Sadly, we have no choice but to lay these out. Some of these you're going to think are common sense, but if it's here someone has done it before. You'd be surprised at the things that some writers try to get away with!
Meta-gamers use out-of-character knowledge when writing in character, making their character know things they shouldn't or act in ways that should be impossible. This includes using plot details that the game managers have revealed in the briefing but have not been used in the actual simulation posts yet. If your character is an engineer, they do not know what the intelligence officer has found in a report and the intelligence officer does not know what the engineer did to the engines. Until it's been revealed in a post that you are taking part in, pretend you don't know about it!
God-modders are the unbeatable behemoths who win every fight and can never ever lose because they're the best at everything they do. This is boring. It's incredibly grating to read and it has to be boring to write. Every character has weaknesses. If you have no weaknesses, we hate to say it but you're god-modding. The same applies to ships; every ship has weaknesses. There is no unbeatable ship, only ships that we don't yet know how to beat.
A Mary Sue (Gary Stu or Marty Stu for men) is the perfect special snowflake who does no wrong and is oh so important and often saves the day at the last minute. They're the youngest or smartest person to do whatever it is they do. They're charming and lovable and everyone just adores them and then they die and it's so sad.
Ahem. We do not love the Mary Sue. The Mary Sue is annoying. Don't be a Mary Sue, please.
An auto hit occurs when two characters are fighting and one (let's call him Sam) writes along the lines of “Sam hit Dean right in the nose, and blood sprayed everywhere.” That's just unfair to whoever is writing for Dean. You do not get to determine whether your blow did any damage. You might not get to determine whether you even managed to hit your opponent. Discuss the rules of the fight beforehand or use a random dice roll or random number generator.
Auto hits might not get you banned right away, but they will annoy other writers and you will eventually get in trouble. Just don't do it!
Powerplayers write for someone else's character without permission. Surely we don't have to explain why this is extremely rude.